The same thing happens in other circumstances too, when the enter key is used to activate a link or the space key to select a checkbox for example.

When the tab key is pressed it is automatically passed through to the browser where it causes keyboard focus to move to the next piece of interactive content, exactly as though the screen reader weren’t running. Not all keypresses are captured by the screen reader however. The copy of the original document is generally referred to as the virtual buffer. In JAWS this mode of interaction is known as virtual mode, and in NVDA and Window-Eyes as browse mode.

It is also possible to open dialogues that list all the elements of a particular type – for example form controls or links. Most Windows screen readers follow a broadly similar shortcut convention: For example t moves focus to the next table, h to the next heading, l to the next list, g to the next graphic and so forth. This behaviour also makes it possible to navigate through content using shortcut keys that are native to the screen reader. This happens because the screen reader intercepts most keypresses before they reach the browser, triggering an interaction with the virtual document instead.įor example the left/right cursor keys are intercepted and used to move focus to the previous/next character in the content, and the up/down keys move focus to the previous/next line instead of scrolling the page. The DOM is a hierarchical representation of the objects in the web-document, and the information that’s retrieved from it is augmented by the screen reader and displayed to the user as a virtual copy of the original.īy creating a virtual copy of the document, screen readers make it possible for blind people to interact with content in ways that would otherwise be impossible on the Windows platform. When a document is rendered in the browser, Windows screen readers like JAWS and NVDA access the Document Object Model (DOM) either directly or through the available accessibility APIs. This post explains why Windows screen readers behave the way they do, and how your code can influence that behaviour. Windows screen readers have multiple modes of interaction, and depending on the task being carried out they’ll automatically switch to the most appropriate mode.

What is nvda screen reader